Spring assembly and method of making the same

ABSTRACT

A spring structure comprising a rigid border wire rectangular in configuration having spaced parallel ends and sides, spaced pairs of parallel wires fixed to the border wire transversely and longitudinally thereof, said pairs of wires crossing at right angles and providing at their intersections end supports for the ends of coil springs, said border wire and pairs of crossing wires comprising a rigid grid, the pairs of wires in one direction containing between the pairs of wires in the other direction depressions which extend from the lower side of the grid, a plurality of coil springs mounted to the lower side of the grid with their axes perpendicular thereto and with their ends engaged with the grid and with said depressed portions of the wires, and locking wires extending from border wire to border wire of the grid between the ends of the coils and said depressed portions of the wires in directions at right angles to the wires containing the depressions.

United States Patent Garceau [54] SPRING ASSEMBLY AND METHOD OF MAKING THE SAME [7 21 Inventor: Harry A. Garceau, Charlton City, Mass.

[73] Assignee: Webster Spring Co. Inc., Oxford, Mass. 22 Filed: May 18, 1970 [21] App]. No.: 38,266

[ 1 May 9, 1972 Primary Examiner-Casmir A. Nunberg Attorney-Roberts, Cushman & Grover [57] ABSTRACT A spring structure comprising a rigid border wire rectangular in configuration having spaced parallel ends and sides, spaced pairs of parallel wires fixed to the border wire transversely and longitudinally thereof, said pairs of wires crossing at right angles and providing at their intersections end supports for the ends of coil springs, said border wire and pairs of crossing wires comprising a rigid grid, the pairs of wires in one direction containing between the pairs of wires in the other direction depressions which extend from the lower side of the grid, a plurality of coil springs mounted to the lower side of the grid with their axes perpendicular thereto and with their ends engaged with the grid and with said depressed portions of the wires, and locking wires extending from border wire to border wire of the grid between the ends of the coils and said the wires containing the depressions.

7 Claims, 13 Drawing Figures BACKGROUND OF THE INVENTION It is cutomary in the manufacture of spring structures such as are used for box springs, inner spring mattresses and upholstered furniture, to provide a border wire with longitudinally and transversely extending cross-wires secured at theirends to the border wire and then to secure the end loops of a plurality of coil springs to the grid at spaced positions both transversely and longitudinally with clips, twists of wire or by welding, and/or combinations of .the aforesaid means. In some instances, the crossing wires of the grid have been provided with depressed portions where the ends of the coils are to be seated and locking wires have been placed between the ends of the coils and the depressed portions of the wires to attach the ends of the coils to the grid. The use of clips, twists of wire and welding requires that each connection be carried out as a separate operation so that to complete the numerous fastenings for a single spring assembly takes considerable time. Locking wires for making a plurality of connections at one tim as heretofore employed, while to some extent eliminating the individual'fastenings and hence speeding up manufacture have not anchored the ends of the coils satisfactorily to the grid and have provided little stability. Also in spring manufacture, as is known, the bulkiness of the structure makes it difficult to provide adequate storage space at the plant and adequate space for shipping. To solve the space problem, it is customary to compress the spring structures and to tie them in bundles thus compressed with strapping. This requires special apparatus and adds to the cost of manufacture. This invention has for its purpose to simplify the manufacture of spring structures by lessening the necessity of having to make individual connections and to eliminate the necesand there are looking elements extending in both directions;

FIG. 11 is a fragmentary elevation taken on the line 11- 11 ofFIG..10;

sity for stacking the finished structures incompressed conditions at the plant and during shipping by supplying the component parts of the structure substantially flat and unassembled to the ultimate userin such condition as to be easily assembled to form the completed structure without requiring special machinery and/or specially trained operators.

SUMMARY As herein illustrated, the spring structure comprises a stiff border wire of rectangular configuration across which are disposed a plurality of pairs of longitudinally and transversely extending, spaced parallel wires connected at their ends to the border wire, the pairs of wires in one direction containing at at right angles to the pairs of'wires containing the depressions.

The pairs of wires in the other direction may also contain depressions and there may be locking wires extending between the end loops and these latter depressions.

The invention will now be described in greater detail with reference to the accompanying drawings wherein:

FIG. 1 is a plan view of a gridbroken away in part with coils attached thereto according to the invention;

FIG. 2 is a very much enlarged fragmentary plan showing the crossing of a single pair of wires in each direction and a locking wire securing an end of a coil to one of the pairs of wires of the grid;

FIG. 3 is a fragmentary elevation taken on the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary section taken on the line 4-4 of FIG. 3;

FIG, 5 is a perspective looking down at the top of FIG. 2;

FIG. 6 is a perspectiveof the complete spring assembly;

FIG. 12 is a perspective looking down on the top of FIG. 10, omitting the locking elements; and

FIG. l3is a perspective similar to FIG. 12 of an alternative structure in'which the depressions are continuous in the pairs of wires in one direction and discontinuous in the pairs of wires in the other direction. A

Referring to the drawings, the spring structure herein illustrated comprises essentially a grid 10 of substantially rectangular configuration, a plurality of coiled springs 12 which, as herein illustrated, are of tapering construction, and a plurality of locking wires 14 by means of which the coils are secured to the grid with their larger ends secured to the grid and with their axes substantially perpendicular thereto.

The grid 10 is comprised of a rigid border wire having spaced parallel sides 16-16 and spaced parallel ends 18-18 and transversely of this grid are secured a plurality of pairs of wires 20 and 22. The pairs of wires are spaced both transversely and longitudinally at uniform intervals, the distance between pairs of wires being determined by the ultimate specifications for the assembly according to strength, springiness, economy of manufacture and the like. The ends of the wires of each pair of wires are secured to the border wire by any suitable means, for example, by welding, by twists of wire or by the means of clips, the aforesaid fastenings being conventional in the art of spring manufacture.

The spacing of the wires in each pair of wires is such that where one pair crosses another pair a seat is provided for the end of the coil which is to be attached to the grid. The spacing of the wires in one pair, for example the pair 20, must be less than the diameter of the large end of the coil so that the end of the coil overlaps these wires and the wires themselves are provided with depressions 24-24 which extend downwardly from the lower side of the grid, each comprising downwardly bent portions 24a-24a and a horizontal portion 24b (FIG-3). The spacing of the pairs of wires 22 in the opposite direction may be greater than the diameter of the end of the coil, or, if desired, to provide for greater seating and stability of the same spacing as the pairs of wires containing the depressed p0rtions. Preferably, the pairs of wires are spot-welded at their crossings with each other as shown at 26; however, again, the fastenings of the wires to each other may be provided for by other means such as by twisting wire about the crossings or by applying clips to the crossings. The wires 22 containing the depressions underlie the wires 20 so that the end loops of the coils will have a flat seat even if the wires 22 have the same spacing as the wires 20.

The border wire and pairs of transversely and longitudinally extending wires secured thereto provide a sturdy top grid for the attachment of the coil springs, each crossing of pairs of wires providing a seat for the end of a coil to be attached thereto.

The coils 12 are of conventional construction and as herein illustrated are tapered, having an upper or end loop 28 loop and of larger diameter than the lower loop 30. The upper loop 28, as illustrated in FIGS. 2 and 3, is of such diameter as to receive the depressed portions 24-24 of the wires 20-20 v with. depressed portions 24-24 at opposite, diametrically disposed sides with respect to the center and with the bent portions 24a-24a frictionally engaged within the end loop and with the horizontal portion 24b below the plane of the top loop and substantially parallel thereto and to the grid, The spacing of the wires 20-20 is selected so that the depressed portions 24-24 will be wedged into the diametrically disposed sides of the top loop and will thus fix the end loop, that is, stabilize it so that it has little tendency to rock or rotate on its seat.

The coils 12 are locked in the aforesaid position by locking elements in the form of wires 32 which are disposed transversely of the wires containing the depressions between the top loops 28 and the horizontal portions 24b of the depressions 24. The locking wires 32 extend across the grid from border to border and preferably the ends are secured to the border wire by welding, twists of wire or clips.

While the locking elements 32 are shown in FIGS. 1 to 6, inclusive, in the form of wires of round cross-section, straps 32a of rectangular configuration may be employed in place of the round wire as shown in FIG. 7, which have the advantage that they are less likely to shift transversely and provide for greater strength.

The completed spring structure, as shown in FIG. 6, comprises the rectangular border wire 16 across which are disposed the spaced parallel pairs of transversely and longitudinally extending wires 20, 22, the wires of the pairs 20 containing the depressions 24 and a plurality of coiled springs 12 secured at their larger ends with their axes substantially perpendicular to the underside of the grid by means of the locking elements 32, 32a extending between the ends of these coils and the depressions in directions at right angles to the wires containing the depressions. Such a structure is adapted to be built into a frame in conventional fashion for making a box spring or to provide a frame for use in furniture manufacture.

As related above, it may be desirable to employ the same spacing between the pairs of wires in each direction so as to provide a seat for the end loops of the coils at four sides, for example, as shown in FIG. 8, wherein the wires 34 have the same spacing as the wires 36. In this structure, the wires of each pair of wires contain depressions 38 and 40 and these are of such length that the ends of the respective depressions lie on circles which correspond in diameter to the inside diameters of the end loops of the coils to be attached to the grid. A locking element 42 in the form of a wire is inserted between the end loop of each coil and the depressions in the pairs of wires in one direction, to wit, the depressions 38 in the wires 34, as shown in FIG. 8, without inserting locking elements in the opposite direction. In this form the depressions 40 in the wires 36 function in cooperation with the depressions 38 to effect centering of the end loop and assist in resisting rotation of the end loop on its seat.

If additional locking is desired, a structure such as shown in FIG. may be employed, wherein the wires of each pair of wires 34 and 36 are provided with depressions 38 and 40 and to accommodate the additional locking element 44 the depressions 40 are made deeper than the depressions 38 so that the locking elements 44 can be inserted beneath the locking elements 42.

Although the depressions in the wires of the respective pairs of wires are illustrated in FIG. 12 as being of the same length by reason of the fact that the wires of the pairs of wires are at the same spacing from each other, the pairs of wires in one direction can be closer together than those in the other direction, provided the maximum spacing is substantially less that the diameters of the end loops of the coils.

Still another form of the structure is illustrated in FIG, 13 in which the wires of the pairs of wires 46 in one direction have continuous depressions 48 and the wires 50 in the pairs of wires in the opposite direction have discontinuous depressions 52 between which there are undepressed portions 54. In using a structure of this kind the locking elements 56 are inserted between the end loops and the continuous depressed portions 48. The spaced depressed portions 52 merely serve to center the end loops with greater certainty and assist in preventing rotation of the end loops relative to the grid.

The spring structure, as related above, embodies constructional advantages over conventionally manufactured springs in that it is especially adapted to gang assembly and welding manufacture to reduce the overall cost of manufacture. This structure has in addition a very special advantage in that the component parts, to wit, the grid, the coils and the anchoring wires may be supplied at the place of manufacture and sent to the ultimate user before assembly, that is, the grids, since they are flat, may be bundled without taking up space such as a completed spring would take up, the coils may be telescoped into each other so that they occupy a minimal space and the locking wires may be bundled in parallel relation. At the place of use the components can be easily assembled by placing the grid bottom side up on a table or other horizontal support, holding the larger ends of the coils against the bottom side of the grid and then inserting the locking wires between the end coils and the depressed portions of the cross wires. Having threaded the locking wires through, the opposite ends are fastened to the border wire as related above. Optionally, the assembly may be facilitated by using a suitably constructed jig designed to hold the grid and coils in engagement while the locking wires are inserted and secured.

The invention embraces, accordingly, not only a novel spring structure per se, but an article of manufacture comprising a plurality of components especially adapted to be assembled together to provide such a structure and a method of making the structure.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents falling within the scope of the appended claims.

I claim:

1. A grid comprising one component of a spring assembly in which a plurality of coils are attached at one end to one side of the grid by a plurality of locking wires, said grid comprising a rectangular border wire, longitudinally and transversely spaced pairs of spaced parallel wires crossing the border wire and fixed at their ends to the sides and ends of the border wire, said crossing pairs of wires providing coil and end seats of substantially rectangular configuration and said wires of the pairs of wires in one direction having a spacing which is less than the diameters of the loops of the coils to be attached thereto against said seats, said wires containing depressions characterized in that each depression is trapezoidal in configuration having spaced downwardly bent end portions joined by a straight portion at the converging ends thereof, said straight portion being of substantially greater length than the combined lengths of the said bent ponions, said trapezoidal depressions being adapted to extend into the end loops wedgingly and being adapted to be held wedgingly engaged therein with the bent portions cordially engaged with the loops by said locking wires.

2. A spring assembly comprising a border wire, a plurality of pairs of longitudinally and transversely extending spaced parallel wires connected at their ends to the border wires, the pairs of wires in one direction between the pairs of wires in the other direction containing depressed portions, coils mounted at the crossings of the pairs of wires with the depressed portions extending into their end loops and locking element disposed between the end loops and the bottoms of the pairs of depressions, said depressed portions being characterized in that each is trapezoidal in configuration having spaced downwardly bent end portions joined by a straight portion of greater length than the combined lengths of the bent portions, said trapezoidal depressions extending into the end loops wedgingly and being wedgingly held engaged therewith with the bent portions chordally engaged with the loops by said locking elements.

3. A grid according to claim 1, wherein the wires where they cross otherwise are secured to each other.

4. A structure according to claim 1, wheriin the wires containing the depressions underlie the wires at right angles, providing a flat seat for the end loops of the coils.

7. A spring assembly according to claim 2, wherein the pairs of wires in one direction contain depressed portions, the ends of which lie on a circle whose diameter corresponds substantially to the inside diameter of the end loops of the coils and the pairs of wires in the other direction contain longitudinally spaced depressed portions between which there are undepressed portions, the outer sides of said spaced depressed portions lying on said circle.

* i t I I 

1. A grid comprising one component of a spring assembly in which a plurality of coils are attached at one end to one side of the grid by a plurality of locking wires, said grid comprising a rectangular border wire, longitudinally and transversely sPaced pairs of spaced parallel wires crossing the border wire and fixed at their ends to the sides and ends of the border wire, said crossing pairs of wires providing coil and end seats of substantially rectangular configuration and said wires of the pairs of wires in one direction having a spacing which is less than the diameters of the loops of the coils to be attached thereto against said seats, said wires containing depressions characterized in that each depression is trapezoidal in configuration having spaced downwardly bent end portions joined by a straight portion at the converging ends thereof, said straight portion being of substantially greater length than the combined lengths of the said bent portions, said trapezoidal depressions being adapted to extend into the end loops wedgingly and being adapted to be held wedgingly engaged therein with the bent portions cordially engaged with the loops by said locking wires.
 2. A spring assembly comprising a border wire, a plurality of pairs of longitudinally and transversely extending spaced parallel wires connected at their ends to the border wires, the pairs of wires in one direction between the pairs of wires in the other direction containing depressed portions, coils mounted at the crossings of the pairs of wires with the depressed portions extending into their end loops and locking element disposed between the end loops and the bottoms of the pairs of depressions, said depressed portions being characterized in that each is trapezoidal in configuration having spaced downwardly bent end portions joined by a straight portion of greater length than the combined lengths of the bent portions, said trapezoidal depressions extending into the end loops wedgingly and being wedgingly held engaged therewith with the bent portions chordally engaged with the loops by said locking elements.
 3. A grid according to claim 1, wherein the wires where they cross otherwise are secured to each other.
 4. A structure according to claim 1, wheriin the wires containing the depressions underlie the wires at right angles, providing a flat seat for the end loops of the coils.
 5. A spring assembly according to claim 2, wherein the depressions in the pairs of wires in one direction are greater than the depressions in the pairs of wires in the other direction, and wherein there are locking wires disposed between the end loops and the bottoms of the depressions in the pairs of wires in both directions.
 6. A spring assembly according to claim 2, wherein the depressions in the pairs of wires in each direction are of the same length.
 7. A spring assembly according to claim 2, wherein the pairs of wires in one direction contain depressed portions, the ends of which lie on a circle whose diameter corresponds substantially to the inside diameter of the end loops of the coils and the pairs of wires in the other direction contain longitudinally spaced depressed portions between which there are undepressed portions, the outer sides of said spaced depressed portions lying on said circle. 